And I forgot to say the most important thing:
Call your doctor's office and tell them about the rash. It might be a reaction to the medication you are on.
Are you in the US now, or somewhere else? There are different strains of Lyme and similar diseases in different parts of the world.
Your rash could be a new infection, and it could be a new infection with Lyme, or your old infection becoming active again after your more recent bite.
Different co-infections (meaning infections that come from the same ticks that carry Lyme) sometimes need drugs different from the drugs that treat Lyme. That could be a reason you don't feel you are reacting to the meds you are on now.
Also, co-infections require different blood tests from Lyme.
I would suggest you look around on line for photos that look like your rash, so that you can talk to your MD about further testing. The common co-infections are Rickettsia (also called ehrlichiosis), Babesiosis, bartonella, mycoplasma, and a few others.
If you google (or otherwise search online) for images of 'flat red rash' or each name of the co-infections above, it might give you some ideas to present to your doctor.
I hope you are feeling better soon ... and by the way, your English is excellent, and needless to say, much better than my Romanian. :) Let us know how you do, okay?